Well $3,000 is a lot to spend on just iPod listening cans. I'd suggest that you buy a cheaper pair for out & about use, plenty to choose from at $200-500 and a more specialised pair for home use which will cost between 800-1500, of course these will need a decent amp to drive them. You don't say what your home system is.

Sennheiser HD650 or HD800 are said to be some of the best headphones ever. There are more expensive models that might see some slight improvement but not straight from the HO of an iPhone. Headphones of these types are more suited to sources such as HiFiman HM801/Colorfly C4 Pro. Very high quality headphones are often high impedance ie. 150/300/600 Ohms which make them hard to drive with small portable media players in some cases. Headphone amps. are used to eliminate the problems of low volume and distortion at high volumes with high resistance headphones. You might want to spend some money on a headphone amp. or even buy another source.

If you want to use from an IPOD, then the highest you can go is for Senn HD 598 level headphones for around $200-400+ tops. Most headphones above $200 need some sort of amping. And when you go to the $500+ range then you need an external DAC as well. So don't expect the setup to be portable.

Yeah, I'd do dual phones though the JH IEMs are highly regarded. Some get tired of something in their ear all the time. If you custom mold them, active use will be a problem as they will not hold as well as flanges or foams.

I have not heard TH900 but I am intrigued by them. My only hesitation is the super expensive finish, which is sure nice, but I am cheap and only wonna pay for SQ, and I imagine that good deal of TH900 cost is for its stunning looks. Still I hear they do sound wonderful.

The TH900 is not transportable despite its a very easy phone to drive with 25 ohm impedance. And it sounds good out of portable DAP and phones like iPhones, iPods. But the lenghth of its cable, the soft clamping force as well as its luxury looking will give you a lot of troubles on the move, not even mentioning the possibility of getting stolen.